Nonlinear electron transport in Si δ-doped GaAs

✍ Scribed by G. Li; W. Xu; P. Hawker; A.A. Allerman; N. Hauser; C. Jagadish

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 210 KB
• Volume: 17
• Category: Article
• ISSN: 0749-6036
• DOI: 10.1006/spmi.1995.1013

✦ Synopsis

In this paper we report abnormal non-ohmic behaviour observed in Si (\delta)-doped GaAs. We have performed measurements in Hall bar and Van der Pauw geometries in which electron transport phenomena can be studied by looking into the dependence of the device resistance (\boldsymbol{R}{x x}) on the applied current (I) or input power per electron, (\boldsymbol{P}). Transport of electrons in single Si (\delta)-doped layers in GaAs, grown by MOCVD, in the linear and non-linear response regimes was studied. Our experimental results show that: i) (\boldsymbol{R}{x x}) dramatically decreases with increasing (\boldsymbol{I}(\boldsymbol{P})) when sample current (input power) is larger than a critical value (\boldsymbol{I}{c}\left(\boldsymbol{P}{\mathrm{c}}\right)); ii) (I_{c}) increases with electron density ( (\mathrm{Si} \delta)-doping concentration); and iii) the decrease in (\boldsymbol{R}{x x}) with increasing (I) in the non-linear response regime can be observed both at zero and high magnetic fields over a wide temperature range. When (\boldsymbol{R}{x x}) is plotted as a function of the power loss rate per electron ((P)) the values of the critical power (\left(\boldsymbol{P}{\boldsymbol{c}}\right)) for different samples are roughly the same. We suggest that redistribution of the ionised donors in the sample occurring when (I>) (I{c}) takes the major responsibility for the observed abnormal phenomena.